Recently, a lithography technology which uses a self-organizing material (also referred to as directed self-assembly (DSA) material) is developed. A DSA-type material can be used for forming dot patterns, hole patterns, pillar patterns, line patterns, or the like of various sizes, by adjusting molecular weights of components or ratios thereof. In order to form the patterns, a guide for controlling a position at which a polymer phase pattern that is formed by DSA is required. The guide for DSA patterning can include a physical guide (grapho-epitaxy), such as surface grooves or other topographical patterns, and a chemical guide (chemical-epitaxy) which determines a position at which a microphase separation pattern is formed based on patterned differences in surface energy of a surface.
For example, a resist film can be formed on a film to be processed, then a physical guide can be formed in the resist film by patterning the resist film according to optical lithography. For example, a hole pattern to be used as a physical guide can be formed in the resist film. A block copolymer (BCP) material can then be applied to the patterned resist film so as to fill the holes in the hole pattern. The block copolymer film thus applied can be heated. The block copolymer can become phase-separated by this processing. A hole pattern which is smaller than the hole pattern initially formed by the optical lithography process can be obtained by selectively removing a portion of the phase-separated polymer.
In the process to form the smaller hole pattern, a hole diameter is determined by the parameters of the block copolymer material, such as the amount of molecules. Hence, to form patterns having multiple hole diameters that are different from each other, different block copolymer materials would be required for each pattern size. In such cases, a separately performed lithography processes would generally be required for providing the different final pattern sizes corresponding to the different block copolymer materials, and thus, the number of processes and manufacturing costs may increase.